university of kwazulu-natal faculty of science and agriculture school ...

O
CH 3CO
3
2
1
O
OH
5
18
OR
5
11
6
OR
OR
12
8
14
OH
O
R
(160) H
(161) C(O)CH3
11
9
O
6
7
OH
12
8
(165)
14
OH
O
CH 2OR
16
CH2OCCH3 O
CH 2OCCH 3
O
3
1
OH
5
11
9
R 1CH 2 OH
7
OH
12
8
R 2
14
OH
R1 R2
(162) H CH2CH(OH)CH3
(163) OCH(O) CH2CH=CH2
(164) OCH(O) CH2CH(OH)CH3
Compounds 166 and 167 (Table 9c) have double bonds within rings A and B. In
compound 166, the double bonds are located at C-1(10) and ∆ 6 respectively while the
methyl group is no longer at C-10 but at C-5. In 167 the double bonds occur at ∆ 3 and ∆ 5
and the methyl group at C-19 has migrated from C-4 to C-3. The linear, 3-carbon side-
chain in this compound has been oxidized to an alcohol. In compound 166, the
substituent at C-19 is aromatic.
O
67